ABSTRACT

Gregory T. Whiteker, John R. Briggs, James E. Babin, and Bruce A. Barner The Dow Chemical Company, South Charleston, West Virginia, U.S.A.

ABSTRACT

Bisphosphite ligands were originally discovered at Union Carbide and have been extensively studied for olefin hydroformylation. Structural modification of bisphosphite ligands allows their use in asymmetric catalysis. These chiral bisphosphites lead to the highest combination of branched regioselectiviry (b/1) and enantioselectivity (%ee) of any asymmetric hydroformylation catalyst reported to date. These catalysts have been applied to a highly efficient synthesis of S-Naproxen. In addition, the use of chiral bisphosphites in asymmetric olefin hydrocyanation is described. Details of the structural features responsible for high b/1 and %ee in asymmetric hydroformylation and hydrocyanation are presented.